[John Rogers]

The info about all the other pumps besides reactor cooling pumps is pretty much true and most of those are run 98% of the time. Only on "silent running are all mechanical things shut down or turned off and in that case only the electric motor and it's shaft connected to the propeller running. Even the prop is shaped so there is no noise from cavitation or water noise. That is why in pictures of our subs in dry dock show a cover over the prop and in some cases are guarded. Surface ships also cover their sonar dome on the bow of the hull so it can't be seen?

One of the Spruance class destroyers hit a whale off the coast of Australia and put a long gash in their sonar dome. They limped back to San Diego, were put in the dry dock and a replacement dome sent by C5 Galaxy from the east coast. It landed at NAS North Island and immediately ran into a HUGE problem......seems the rubber/cloth/sealer the dome is made of is poison so those pesky sea creatures will not grow in it! Well San Diego would not give permission to cross the bridge, so the state gave permission to truck it down the "strand", through Imperial Beach the up interstate 5 to Naval Station San Diego with the roads all being shut down and then checked to insure no contamination had occurred. The old dome was removed inside a huge tent and all the workers had security clearances and wore protective suits. Total cost in 1986 was about 6 million dollars give or take a little. I was one of the two SupShip QA people assigned to insure NASSCO did the job correctly.
John